Chinese nuclear reactors did not get safety tests before installation
South China Morning Post reported that 2 new nuclear reactors in Taishan, Guangdong, did not undergo the same quality tests as a similar reactor in France that was found to have weak spots prone to cracks.
France’s Nuclear Safety Authority said that special tests at the Flamanville EPR nuclear power plant were only carried out last year after France tightened its nuclear safety regulations.
No such tests were conducted on the two third-generation EPR Taishan reactors before French nuclear manufacturer Areva shipped them to China.
That meant the CNY 50 billion Taishan plant, located about 80km west of Zhuhai and Macau, could be plagued by the same problem and not be detected.
Weak spots in a reactor’s steel shell is a serious defect, once installed, the shell cannot be replaced throughout the reactor’s 60 year lifespan.
The tests in France found that excessive carbon in the steel that formed the reactor’s top and bottom could lead to unexpected cracks that could later spread.
The news comes as a shock to China’s burgeoning nuclear sector. With the completion date of the first project phrase expected by the end of this year, the Taishan EPR plant was a landmark project for China’s nuclear sector.
The plant’s two advanced 1.75 GW pressurised water reactors were to be the world’s largest single-piece electric generators and their operation was said to be the safest, too.
An EPR reactor vessel similar to the ones installed in Taishan. Graphic: ASN
Now it is not certain whether the Taishan reactors would comply with France’s stricter standards.
The ASN said that “Manufacturers must perform non-destructive tests on their products to guarantee their compliance. However, some mechanical properties can only be measured by destructive tests, which cannot be performed on delivered equipment.”
It said that “Following a revision of the French regulations in 2005, ASN has required manufacturers to perform destructive and non-destructive tests on equipment to qualify their manufacturing process. For the domes of the EPR main pressure vessel, those tests were performed in October 2014. Areva performed extensive non-destructive tests on all reactor vessel equipment, including on those shipped to China. But, as explained previously, the problem can only be detected by destructive tests.”
However, the ASN said that Areva had a come up with a plan to deal with the problem.
It said that “Over the next few months, Areva plans to perform comprehensive tests on equipment made with the same manufacturing process to fully characterise the problem, assess its impact on the safety of the reactors, (and) if need be, provide additional justifications and/or propose compensatory measures.”
The ASN said that China’s National Nuclear Safety Administration were informed about the problem were provided with information on Friday last week.
Areva said that the Taishan reactors met Chinese nuclear standards.
The company said that “The reactor vessel heads for the Taishan reactors were evaluated as being in compliance with the Chinese regulations. The French and Chinese safety authorities are in contact following the information provided by the French watchdog.”
Source : SOUTH CHINA MORNING POST